INTUMESCENT FIRE PROTECTION COATINGS

Abstract: A non-halogen-containing, water-based, intumescent fire protection composition is presented which dries or cures to an intumescent, fire protection coating. The compositions comprise an aqueous ethylene vinyl acetate binary copolymer and zinc oxide. Methods of imparting fire resistance to surfaces, and articles having at least one surface coated with a coating derived from inventive composition, are also presented.

Description: INTUMESCENT FIRE PROTECTION COATINGS BACKGROUND OF THE INVENTION This invention relates to coating compositions which impart fire-resistance to surfaces and in particular to water-based, non-halogen-containing intumescent, fire protection coating compositions. Fire resistance performance of coating compositions has generally been achieved or enhanced by the incorporation of halogenated materials. These types of materials have considerable drawbacks in terms of smoke production and toxicity concerns, relating both to combustion products and also to disposal of the compounds themselves. There is a desire towards the replacement of these flame retardants by zero halogen alternatives. A further limitation of the use of halogenated flame retardant coatings is that during combustion they emit large amounts of corrosive smoke. Combustion products of halogen containing materials, in particular HC1 and HBr, contribute significantly to these effects. The corrosivity of smoke is of particular importance in electrical/electronic applications, since a small fire involving halogenated insulation materials may generate sufficient corrosive combustion products to cause widespread damage to other equipment not directly involved in the fire. A limitation of intumescent coatings is that the expanded char produced during fire exposure is of limited strength and durability. Eventually, the char is converted to ash and falls away. This factor limits the degree of protection that may be provided to a substrate. It has now been found that non-halogen intumescent coatings having good char strength and burn through resistance may be obtained by employing the combination of zinc oxide and a particular binder. According to the present invention there is provided a non-halogen-containing, water-based, intumescent fire protection composition comprising an aqueous ethylene vinyl acetate binary copolymer latex and zinc oxide. Coatings derived from the compositions of the invention, when dried or "cured", may be used as a surface covering for penetration seals to improve thermal insulation of mineral wool based systems, and as a cable coating to provide a barrier against flame spread. The compositions may be applied in a similar manner to paint, e.g., by brushing or spraying. The compositions of the invention preferably dry to a white flexible film coating. When heated in a fire, the coating expands by up to twenty times in volume to form a thick insulating layer of fire resistant char. More viscous compositions in accordance with the invention may be extruded through a nozzle and used as intumescent fire barrier caulks, sealants and mastics. The term "coating" as used herein means a dried or cured material, whereas the term "composition" means a sprayable or brushable material. Coatings derived from compositions of the invention display excellent fire resistance properties and exhibit low smoke and toxic gas production upon combustion. In particular, a surprisingly high char strength and high burn through resistance is exhibited which is attributable to the presence of the combination of the thylene vinyl acetate binary copolymer (EVA) binder and zinc oxide. The use of ethylene vinyl acetate copoly ers as water-based latex binders is known, although grades additionally incorporating vinyl chloride monomer are normally preferred as the halogen content confers additional fire resistance. The present invention employs as a binder binary copolymers of ethylene and vinyl acetate, i.e., copolymers that do not contain significant numbers of repeat units that are derived from monomers other than ethylene and vinyl acetate. As is well known in the art of polymer chemistry, copolymers seldom exist as well-defined "pure" compounds, but rather as statistical mixtures of chains of different lengths in which the monomer repeat units may be distributed in a random or non-random fashion. Impurities in the starting monomers and side reactions during (or after) polymerization can introduce minor amounts of additional functionalities on the chains. Such "impurities" are usually impossible to separate or eliminate from the intended product. For the purposes of the present invention, it is assumed that up to 5% of the repeat units of the binder polymer may bear functionalities other than those derived directly from ethylene or vinyl acetate, but preferably no more than 3% of the repeat units bear such functionalities, most preferably no more than 1% . The EVA latex binder is generally present in an amount such that the EVA provides at least 7.5%, usually from 7.5 to 35%, preferably about 16.5% of the total weight of solids of the composition. As used herein the term "% weight of solids" means the % weight of material in the inventive composition which remains on a substrate as a coating. A suitable binder is commercially available under the trade name "Vinnapas" EZ-36 from Wacker. Terpolymers comprising vinyl acetate, ethylene and a further monomer e.g., vinyl chloride, acrylate etc. are not suitable for use in the invention. The use of zinc oxide as a filler in polymeric formulations is known; for example, Handbook of Fillers for Plastics, eds . Katz and Milewski, Van Nostrand Reinhold (1987) , p235, discloses that zinc oxide may be used to improve resistance to weathering, and promote hardness, heat stability, and electrical conductivity of polymers. Zinc oxide has also been used as a synergist with halogen containing flame retardant materials, e.g., as disclosed by Cullis and Hirschler in pp291 to 293 of The Combustion of Organic Polymers, Oxford University Press (1981) . There as been no disclosure of the use of zinc oxide in a non-halogen EVA latex based intumescent compositions . The zinc oxide is generally present in an amount of at least 0.15%, usually in the range 0.75 to 7.5% by weight based on the total weight of solids in the composition. The preferred range is 1.0 to 3.0%. Higher concentrations may give reduced levels of intumescence. If the zinc oxide is absent or replaced by another material, such as titanium oxide, the char strength and burn through resistance of the coatings derived from the compositions are deleteriously affected. The inventive compositions additionally comprise an intumescent system, e.g., a spumific, such as melamine, in combination with an acid forming catalyst, such as ammonium polyphosphate, and a carbonific material, such as pentaerythritol . Additional intumescent materials may be added, such as glass frits, sodium silicate or alkali metal silicate/borate mixtures as described in U.S. Patent No. 4,521,333. The use of silicate granules in intumescent materials is described in European Patent Application No. 0346001. The compositions may further comprise one or more of the following optional additives: pigments, e.g. titanium dioxide, iron oxides coalescing agents, e.g., white spirit, 2,2,4- trimethyl-1,3-pentanediol, thickeners, e.g., cellulose ether, fumed silica, aqueous acrylic dispersions, reinforcing agents, e.g., talc, a mixture of mica, quartz and chlorite, fungicides, e.g., 2-n-octyl-4-isothiazolin-3-one, polyacrylate, sodium polyphosphate, and pH adjusters, e.g., sodium hydroxide. Other materials which are used as additives in water- based paints may also be employed. A typical and preferred composition within the invention would be as follows : Parts by Weight Water 5 to 30 Cellulose ether up to 5 NaOH up to 2 (of aqueous solution e.g. , 10% solids) Sodium up to 5 (of aqueous solution polyphosphate e.g. , 10% solids) EVA latex 10 to 40 (of aqueous dispersion e.g. , 55% solids) 2-n-octyl-4- up to 0.5 isothiazolin- 3-one Titanium dioxide up to 10 Zinc oxide 0.5 to 5 Pentaerythritol 5 to 25 Ammonium 5 to 25 polyphosphate Melamine 5 to 30 2,2,4-trimethyl up to 5 1, 3-pentanediol Talc up to 25 The components of the compositions may be mixed in equipment commonly used for the preparation of water- based paints, including planetary mixers and high dispersion mixers. Depending on their viscosity, the compositions of the invention may be applied in the same way as a water-based emulsion paint, e.g., by brushing, roller coating, dipping and spraying to a variety of surfaces, or extruded through the nozzle of a caulk gun. The normal applied thickness is in the range of 0.2 to 5 millimeters. The fire protection effectiveness of the coating increases with film thickness. The compositions may be used to provide a fire resistant seal to mineral wool based electrical and mechanical through penetrations, e.g., cables, cable trays, steel pipes, when used as a coating on the mineral wool board and penetrating items. The inventive compositions may also be applied to cables to provide coatings which suppress flame spread. By protecting the cable insulation from combustion, the coating will thereby reduce the generation of toxic and corrosive HC1 gas from polyvinylchloride insulated cables. The intumescent coating expands many times in a fire to produce a high volume of protecting char and therefore only a thin coating layer needs to be applied to the cables which does not significantly affect the radiation of heat from cables during normal current carrying operation. The invention will now be illustrated by the following Examples. In the Examples, the following materials were used, where quotation marks designate trade designations: "Natrosol" 250GR, Hydroxyethylcellulose commercially available from Aqualon UK Ltd, Warrington; Calgon "P/T", a sodium polyphosphate glass commercially available from Calgon and formulated as a 10% by weight solution in water; Pigment Distributor A, an ammonium salt of polyacrylate commercially available from BASF AG, Ludwigshafen; "Vinnapas" EZ-36, an aqueous dispersion of copolymer of vinyl acetate and ethylene commercially available from Wacker-Chemie GmbH, Munchen; "Vinnapas" CEZ-16, an aqueous dispersion of terpolymer of vinyl acetate and ethylene and vinyl chloride commercially available from Wacker-Chemie GmbH, Munchen; "Vinnapas" EAF-60, an aqueous dispersion of terpolymer of vinyl acetate and ethylene and acrylate commercially available from Wacker-Chemie GmbH, Munchen; Pentaerythritol "D/S", fine ground pentaerythritol commercially available from Degussa AG, Hanau; "Texanol", 2,2,4-trimethyl-l,3-pentanediol monoisobutyrate commercially available from Honeywill & Stein Ltd., Sutton; "Exolit" 422, ammonium polyphosphate commercially available from Hoechst UK Ltd., Halifax; Melamine 003, melamine commercially available from DSM Chemicals BV, Urmond; "Byk-035", a mixture of hydrophobic components in paraffin based mineral oil functioning as a defoaming agent commercially available from Byk-Chemie, Wesel; Titanium dioxide, "Bayertitan" R-KB-4 commercially available from Bayer AG, Leverkusen,- "Plastorit Naintsch" 0.25, a mixture of mica, quartz and chlorite commercially available from Naintsch Mineralwerke Ges.m.b.H, Graz; "Zinc oxide-10", ZnO commercially available from Durham Chemicals Ltd., Birtley; White spirit, a petroleum distillate commercially available from Alcohols Limited, London,- "Skane M-8", 45% 2-n-octyl-4-isothiazolin-3-one in propylene glycol commercially available from Rohm & Haas UK Ltd., Croydon; "Rohagit" SD15, an aqueous dispersion of . acrylic resin based on acrylester and methacrylic acid commercially available from Rohm GmbH, Darmstadt; "CabOSil" M5, fumed silica commercially available from Cabot Corporation, Tuscola,- "Pyrosafe Flammoplast" KS-l, an intumescent coating commercially available from SVT Brandschutz Vertreibsgesellschaft MBH International, Seevetal; "Fomox WMP", an intumescent mastic-coating commercially available from Bayer AG, Leverkusen,- Intumescent coating 38104 commercially available from Hilti France, Paris; "Orgol FS", an intumescent coating commercially available from Minnesota Mining and Manufacturing Company, Saint Paul, Minnesota; and "FireDam" 150, a caulk commercially available from Minnesota Mining and Manufacturing Company, Saint Paul, Minnesota. Examples 1 to 5 disclose the preparation of intumescent compositions of this invention. Examples A to H are comparative examples. The fire test performance of the formulations are shown in Examples 14 and 15, and the smoke and toxic gas emission is demonstrated in Example 16. Examples 1 to 5 The compositions of Examples 1 to 5 are detailed in Tables 1 and 2. The compositions of Examples 1 to 4 were mixed in a planetary mixer with two litre capacity with batch sizes of 1 to 2 kg. A planetary mixer, known under the trade designation "Kenwood Chef", with a "K" blade mixing head was used. Mixing speeds were varied throughout the blending process to achieve optimum dispersion. The ingredients were added to the mixing bowl in the order given in Tables 1 and 2 with continuous mixing. Each material was mixed until thoroughly dispersed before adding the next ingredient . When completely blended, the mixtures were stored in an airtight non-metallic container. The composition of Example 5 was mixed in a pilot scale 30 kg batch using a mixing vessel with a high speed dispersion blade and a slow orbital scraper blade. TABLE l Addition Material Parts by Weight order Example 1 2 3 4 5 1 Demineral- 17.6 17.0 12.0 12.0 17.0 ised water 16 Rohagit 0.2 - - 1.0 1.0 SD15 16 CabOSil M5 - 1.0 0.5 - - 17 Byk 035 0.7 - - - - All formulations additionally contain the ingredients of TABLE 2. TABLE 2 Addition Parts by Order Material Weight 2 Natrosol 250GR 0.4 3 NaOH (10%) 0.1 4 Calgon » p/τ" (10%) 2.8 5 Pigment Dist. A 0.3 6 Vinnapas EZ-36 20.5 7 Skane M8 0.1 8 Titanium dioxide 3.1 9 Zinc oxide-10 2.0 10 Pentaerythritol 13.3 11 Exolit 422 13.3 12 Melamine 003 15.6 13 Texanol 0.9 14 White spirit 0.9 15 Plastorit 9.2 Examples 1 to 5 of this invention, all contained both an EVA latex binder ("Vinnapas" EZ-36) and zinc oxide, and were non-halogen formulations. They contained varying amounts of thickening agents . Example 1 also contained a defoamer. These variations in thickener and defoamer content gave rise to slightly different viscosities and coating characteristics of the compositions produced. Comparative Examples A to D Four comparative compositions A-D detailed in TABLES 3 and 4 were prepared using the general procedure of Examples 1 to 4. TABLE 3 Addition Material Parts by Weight Order Example A B C D 1 Demineral- 17.0 15.0 18.7 18.7 ised Water 6 Vinnapas 20.5 - - - EZ-36 6 Vinnapas - 22.5 - - CEZ-16 6 Vinnapas - - 18.8 18.8 EAF-60 8 Titanium 5.0 3.1 3.1 3.1 dioxide 9 Zinc - 2.0 2.0 2.0 oxide-10 16 Rohagit 1.0 0.4 1.0 - SD15 16 CabOSil M5 - - - 0.5 Compositions A-D additionally contained the ingredients of TABLE 4. TABLE 4 Addition Parts by Order Material Weight 2 Natrosol 250GR 0.4 3 NaOH (10%) 0.1 4 Calgon "P/T" (10%) 2.8 5 Pigment Dist. A 0.3 7 Skane M8 0.1 10 Pentaerythritol 13.3 12 Melamine 003 15.6 13 Texanol 0.9 14 White spirit 0.9 15 Plastorit 9.2 In Comparative Example A, an EVA binder was used, but zinc oxide was replaced by additional titanium dioxide. Comparative Examples B to D contained zinc oxide, but with the EVA binder replaced by a terpolymer latex, which was a polymer of ethylene, vinyl acetate and a third monomer. The third monomer was either vinyl chloride ("Vinnapas" CEZ-16, Comparative Example B) or an acrylate ("Vinnapas" EAF-60, Comparative Examples C and D) . Comparative Examples E to H The following commercially available intumescent fire protection coatings were also evaluated as Comparative Examples E to H: Comparative Example No. Source Material E Hilti Intumescent coating 38104 F Bayer Fomox WMP G SVT Pyrosafe Flammoplast KS-1 H 3M Orgol FS Coating Example 14 The utility of the inventive and comparative compositions described in Examples 1-5 and Comparative Examples A-H above was evaluated by coating out samples on aluminum foil, to an approximate wet coating thickness of 3mm, allowing these to dry for at least one week, and then exposing the coated foil to fire using a cone calorimeter. The use of the cone calorimeter to measure rates of heat and visible smoke release is described in American Society of Testing Materials (ASTM) test method E1354 (1990) . In this Example, it was used to provide reproducible combustion conditions for the coating samples. For each material, an approximate 1.5 mm thick sample of dried coating on aluminum foil was exposed for 60 minutes on the cone calorimeter (50kW/m 2 irradiation) in a horizontal orientation, and the initial expansion (after 10 minutes) and final char height (after 60 minutes) were compared. The results are reported in TABLE 5. TABLE 5 Example Char height (mm) (initially 1.5mm thick) Initial After 60 expansion minutes 1 30 20 2 15 to 20 20 3 30 25 to 30 4 30 25 5 30 25 A 30 to 35 <10 B 10 to 15 <5 C <10 not measured D 5 to 10 <5 E 50 <5 F 20 <5 G 50 <5 H 30 <10 All of the materials (with the exception of some of the comparative examples) intumesced greatly initially, but the level of char from the Examples of this invention remaining intact after 1 hour was much greater than for any of the comparative examples . This comparison demonstrates the improvement in burn through resistance or durability of the intumescent char produced by the compositions of the invention. Example 15 In order to demonstrate the effectiveness of the intumescent coating in a mineral wool board based concrete wall penetration seal, a sample of the Composition of Example 1 was used to coat a penetration seal for large scale fire testing in the wall of a 1 m 3 furnace, following in general the ISO 834 standard. Furnace pressure was set to 13 ± 2 pascal. Penetrating items (all 1 m length) were: 1. a steel cable tray (200 x 60 mm) , with power and telephone cables, all coated on a total length of 460 mm symmetrically to wall centre, and 2. a steel pipe of 63 mm diameter, 3 mm wall (not coated) . The rest of the opening (300 x 300 mm) in 10 cm thick light weight concrete wall (density approximately 600 kg/m 3 ) was closed off with mineral wool boards (150 kg/m 3 ) 60 mm thick, cut to fit tight between penetrating items and concrete, and installed on both faces of the concrete wall . The dried thickness of coating used for this test was approximately 1 mm on the faces and cut edges of mineral wool, 0.4 mm on cables, and 0.2 mm on cable tray. Around the perimeter of each penetrating item, a bead of caulk known under the trade designation "FireDam" 150 from 3M, Saint Paul, Minnesota, was applied to work as a cold smoke seal. Coating on mineral wool board was also extended 50 mm onto concrete to form a cold smoke seal . Thermocouples were located on the mineral wool boards and on the penetrating items at 25 mm from wall surface and 25 mm beyond end of coating. Good fire resistance was obtained, with temperature ratings (time to reach 200°C) of at least 120 minutes for cable tray and mineral wool board, at least 90 minutes for cable, and at least 60 minutes for steel pipe. Example 16 In this Example, the levels of emission of smoke and carbon monoxide (CO) produced during combustion of a composition of this invention (non-halogen formulation) were compared with a commercially available intumescent coating which contained chlorine. Samples of coatings on aluminum foil were prepared as described in Example 14, using Compositions X of Example 5 and Comparative Example G (Pyrosafe Flammoplast KS-1, comparative) . Both materials were examined by energy dispersive X-ray elemental analysis (EDAX) . The coating from Example 12 was found to contain chlorine. No chlorine was seen in the coating from Example 5. Both of these materials were subjected to cone calorimeter fire tests as described in Example 14 except that the tests were terminated after 10 minutes. The emissions of smoke (SEA in table) and CO were measured during the test. Cone calorimeter Material peak SEA mean CO (m 2 /kg) (kg/kg) Example 5 (non-halogen) 151.7 0.0052 Comparative Example G 523.0 0.0160 (contains Cl) This comparison demonstrates the reduced smoke and CO emission from the non-halogen example of this invention. Also, since the Examples of this invention do not contain chlorine, there is no possibility of the emission of toxic and corrosive HC1 gas. Example 17 All formations disclosed in previous examples were designed for use as intumescent coatings. In the two formulations shown below, an increased level of Rohagit SD15 thickener was employed to give a higher viscosity material, for a different application. These two formulations have been shown to be suitable for use as a water-based intumescent fire barrier caulk, sealant or mastic. The formulations were mixed as described in Example 1. The ingredients were added in the order and quantities indicated in TABLES 2 and 6. TABLE 6 Addition Material Parts by Order Weight Example 101 102 1 Water 10.0 10.0 16 Rohagit SD15 4.0 5.0 These formulations also contain the materials shown in TABLE 2 above. In order to verify that these two formulations display low degrees of sag when thickly applied to a vertical surface, sag tests were performed. An aluminum block with a 38 mm diameter circular hole fitted with a brass plunger to leave a cylindrical void of depth 9 mm was used for this test. The block was positioned with the void in the top horizontal face, and the void was filled with material to be tested. Any excess material was then removed with a scraper to give a level surface flush with the top of the block. The block was then turned through a 90° angle and the plunger pushed forward until it was flush with the surface of the block, thus expelling the cylindrical plug of test material onto the now vertical face of the block. The distance that the material flowed down the vertical surface of the block was recorded after five minutes . Smaller measured distances correspond to lower degrees of sag, and a value of 10 mm or less indicates that the material has satisfactory performance as a "non sag" caulk. Formulation Example Vertical Sag (mm) 101 7.5 102 2.5 The results indicate that an acceptable non sag caulk performance may be obtained with both materials. Formulation 101 was measured to expand six times when the dried material was heated at 450°C for ten minutes. In this test, the volume of char produced after heating was measured and divided by the original volume to obtain the degree of expansion. The same formulation (101) was also loaded into caulk tubes and expelled through a 3 mm nozzle using a hand operated caulking gun. The material could be easily expelled in this way without the need for excessive force. These results indicate that formulations of this invention may be produced which are suitable for use as an intumescent fire resistant caulk mastic or sealant, in addition to the use of lower viscosity examples as intumescent coatings. Example 18 There is some prior art describing the use of zinc borate in intumescent coatings (see "Zinc borate in intumescent paints", F. Bellingham, Polymers Paint Colour Journal, vol 182, no. 4319 (1992), pp 627-8) . Since the subject of this invention concerns the use of another zinc compound, zinc oxide, two formulations were prepared to investigate the effect of substituting zinc borate for zinc oxide. The formulations were mixed as described in Example 1. The ingredients were added in the order and quantities indicated in TABLES 4 and 7. TABLE 7 Addition Material Parts by Order Weight Example 103 104 1 Water 17.0 17.0 6 Vinnapas EZ-36 20.5 20.5 8 Ti0 2 3.1 - 9 Zinc Borate 2.0 5.1 16 Rohagit SD15 1.0 1.0 These formulations also contain the materials shown in TABLE 2 above. The sample of zinc borate used for these Examples was "Firebrake" ZB fine, United States Borax and Chemical Corporation, Los Angeles. Example Char height (mm) (initially 1.5 mm thick) Initial After 60 expansion minutes 103 15-20 15 104 5-10 * * not measured Although formulation 103 containing 2 parts zinc borate produced slightly improved burn through resistance over the other comparative examples studied, the performance was inferior to that obtainable with formulations containing 2 parts zinc oxide.

Claims: CLAIMS : 1. A non-halogen-containing, water-based, intumescent fire protection composition characterised in that it comprises an aqueous ethylene vinyl acetate binary copolymer latex and zinc oxide. 2. A non-halogen-containing, water-based, intumescent fire protection composition as claimed in claim 1 further characterized by the ethylene vinyl acetate binary copolymer contains less than 3% of repeat units of functionalities other than those derived directly from ethylene or vinyl acetate. 3. A non-halogen-containing, water-based, intumescent fire protection composition as claimed in claim 2 further characterized by the ethylene vinyl acetate binary copolymer contains less than 1% of repeat units of functionalities other than those derived directly from ethylene or vinyl acetate. 4. A non-halogen-containing, water-based, intumescent fire protection composition as claimed in claim 1 further characterized by the zinc oxide is present in an amount of at least 0.15% by weight based on a total weight of solids in said composition. 5. A non-halogen-containing, water-based, intumescent fire protection composition as claimed in claim 4 further characterized by the zinc oxide is present in an amount in the range 0.75 to 7.5% by weight based on said total weight of solids. 6. A non-halogen-containing, water-based, intumescent fire protection composition as claimed in claim 1 further characterized by the ethylene vinyl acetate copolymer is present in an amount of at least 7.5% by weight based on a total weight of solids. 7. A non-halogen-containing, water-based, intumescent fire protection composition as claimed in claim 6 further characterized by the ethylene vinyl acetate copolymer is present in an amount in the range 7.5 to 35% by weight based on said total weight of solids. 8. A non-halogen-containing, water-based, intumescent fire protection composition as claimed in claim 6 further characterized by the ethylene vinyl acetate copolymer is present in an amount of about 16.5% by weight based on said total weight of solids. 9. A non-halogen-containing, water-based, intumescent fire protection composition as claimed in claim 1 further characterized by an intumescent system including a spumific, a catalyst, and a carbonific material. 10. A non-halogen-containing, water-based, intumescent fire protection composition as claimed in claim 9 further characterized by the spumific is melamine. 11. A non-halogen-containing, water-based, intumescent fire protection composition as claimed in claim 10 further characterized by the intumescent system comprises melamine, ammonium polyphosphate and penataerythritol. 12. A non-halogen-containing, water-based, intumescent fire protection composition as claimed in claim l further characterized by one or more components selected from the group consisting of pigments, coalescing agents, thickeners, reinforcing agents, fungicides, dispersing agents, pH adjusters, and defoaming agents. 13. A method of imparting fire resistance to a surface characterized by applying to the surface a composition as claimed in claim 1. 14. A method as claimed in claim 13 further characterized by the surface being selected from the group consisting of mineral wool board, cable, cable tray, concrete, steel, and wood. 15. An article having at least one surface coated with a coating derived from a composition as claimed in claim 1. 16. An article having at least one surface coated with a coating derived from a composition as claimed in claim 4. 17. An article having at least one surface coated with a coating derived from a composition as claimed in claim 5. 18. An article having at least one surface coated with a coating derived from a composition as claimed in claim 6. 19. An article having at least one surface coated with a coating derived from a composition as claimed in claim 7. 20. An article having at least one surface coated with a coating derived from a composition as claimed in claim 9.

Inventors: BUCKINGHAM MARK R, SWAN MIKE D, BUCKINGHAM, MARK, R., SWAN, MIKE, D.
Applicants: MINNESOTA MINING & MFG, MINNESOTA MINING AND MANUFACTURING COMPANY
Application year: 1994
Main classification: C09D5
IPC codes: C09D5